CN112322057A - High-viscosity rubber asphalt and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of rubber asphalt, and particularly discloses high-viscosity rubber asphalt and a preparation method thereof, wherein the high-viscosity rubber asphalt comprises 100 parts of asphalt, 5-15 parts of rubber powder, 2-7 parts of SBS, 0.5-3 parts of oxidized polyethylene wax, 0.04-0.4 part of first crosslinking auxiliary agent, 1-4 parts of aromatic oil and 0.2-0.6 part of second crosslinking auxiliary agent; stirring aromatic oil, SBS and oxidized polyethylene wax, adding a first crosslinking assistant to obtain a polymer mother liquor A, melting asphalt, adding the polymer mother liquor A, stirring at a constant temperature, adding rubber powder, shearing and grinding the mixture at a high speed, adding a second crosslinking assistant, stirring at a constant temperature to obtain the high-viscosity rubber asphalt. The rubber asphalt prepared by the scheme has the advantages that the adhesive force (dynamic viscosity at 60 ℃) between the rubber asphalt and aggregate can meet the requirements of special asphalt pavements, and the rubber asphalt has better high-temperature resistance and water damage resistance.

Description

High-viscosity rubber asphalt and preparation method thereof

Technical Field

The invention relates to the technical field of rubber asphalt, in particular to high-viscosity rubber asphalt and a preparation method thereof.

Background

In recent years, rubber asphalt has been widely used in road engineering. The rubber asphalt is prepared by processing waste tires into rubber powder, combining the rubber powder according to a certain thickness proportion, adding a plurality of high polymer modifiers, fully melting and swelling the rubber powder and the matrix asphalt under the condition of fully blending at high temperature, and shearing and grinding the rubber powder to obtain a modified rubber asphalt material; compared with common asphalt, the high-temperature stability, the low-temperature stability and the elasticity of the rubber asphalt material are greatly improved; meanwhile, the waste tires can be recycled, so that the energy is saved, the environment is protected, and the waste is changed into valuable.

Two important indexes of the high-viscosity modified asphalt are dynamic viscosity at 60 ℃ (usually required to be more than or equal to 50000pa.s) and Brookfield rotary viscosity at 135 ℃ (usually required to be less than 3 pa.s), and other performance indexes are shown in the following table 1 (JT/T860.2-2013). The viscosity of asphalt is essentially a measure of the ability of asphalt to resist relative displacement between molecules, asphalt with high viscosity is not easy to displace between molecules, and asphalt is not easy to deform and has higher stiffness. The higher viscosity indicates that the asphalt is used as a binding material to bind loose aggregates into a whole, and the aggregates are not easy to displace under the action of external force, so that the asphalt has higher strength and shear flow deformation resistance.

The viscosity of the asphalt is reduced along with the increase of the temperature, and the asphalt pavement is easy to generate permanent deformation under the action of vehicle load in summer to form ruts and jostles, so that the service performance of the road is sharply reduced, and the threat to traffic safety is caused. The maximum temperature of asphalt pavement in summer in many areas tends to reach or exceed 60 ℃, which is a dangerous temperature causing deformation of the pavement, and therefore the high temperature deformation resistance of asphalt can be characterized by a viscosity of 60 ℃. The adhesion force of the asphalt and the aggregate is mainly composed of van der waals force, ionic force, mechanical bonding force (formed after the high-temperature asphalt permeates into micropores on the surface of the mineral aggregate and is cooled) and the like, and the mechanical bonding force is strengthened due to the high viscosity of the asphalt, so that the bonding capability of the asphalt to the aggregate is improved, and the water damage resistance of the asphalt is improved. The dynamic viscosity at 60 ℃ of the high-viscosity modified asphalt with the performance up to the standard is high, but the Brookfield rotary viscosity at 135 ℃ is still below 3pa.s, which shows that the high-viscosity modified asphalt still has good workability and construction rolling performance at high temperature.

TABLE 1

The high-viscosity modified asphalt is suitable for paving high-modulus and extremely-hot-area road surfaces, and is particularly suitable for construction and paving open-graded/semi-open-graded permeable asphalt road surfaces.

However, the high-viscosity rubber asphalt prepared by the conventional formula cannot be applied to special pavements with high asphalt viscosity requirements, such as porous noise reduction pavements, drainage pavements and the like.

Disclosure of Invention

The invention provides high-viscosity rubber asphalt and a preparation method thereof, and aims to solve the problem that the high-viscosity rubber asphalt in the prior art cannot meet the requirement of special pavement with high viscosity and is limited in application.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the high-viscosity rubber asphalt comprises, by weight, 100 parts of asphalt, 5-15 parts of rubber powder, 2-7 parts of SBS, 0.5-3 parts of oxidized polyethylene wax, 0.04-0.4 part of first crosslinking aid, 1-4 parts of aromatic oil and 0.2-0.6 part of second crosslinking aid.

The technical principle and the effect of the technical scheme are as follows:

1. in the scheme, the melting point of the oxidized polyethylene wax is about 105 ℃, the softening point of the matrix asphalt is generally about 50 ℃, the oxidized polyethylene wax added into the asphalt has good high-temperature performance and low-temperature performance, the hardness of the rubber asphalt can be improved at low temperature (before the melting point is reached), the high-temperature toughness of the rubber asphalt can be ensured at high temperature, and the effect on the cohesion of the asphalt is very prominent. In addition, after being combined with SBS, the rubber has low temperature flexibility and elasticity of rubber and high temperature toughness of plastic.

Because the oxidized polyethylene wax is a plastic plastomer, the SBS is an elastomer, the two types can form chemical crosslinking under the action of the peroxide crosslinking auxiliary agent, and the formed novel polymer not only contains an SBS chain segment with the characteristics of the elastomer, but also contains a chain segment of the oxidized polyethylene wax with the characteristics of the plastomer. Meanwhile, after chemical crosslinking, the oxidized polyethylene wax can stably exist in an asphalt system, and is not layered or isolated, so that an asphalt product is more stable.

2. The dynamic viscosity of the rubber asphalt in the scheme is high, and the dynamic viscosity at 60 ℃ is improved to 12 multiplied by 10⁴Pa.s, the adhesive force between the asphalt and the aggregate of the asphalt mixture is very strong (the dynamic viscosity at 60 ℃ reflects the cohesive force of the asphalt), the advantages are obvious on the dispersion and leakage loss performance of Kentucky of the asphalt mixture; meanwhile, the high-temperature performance (dynamic stability) of the asphalt mixture is reflected, and the high-temperature performance (dynamic stability) of the asphalt mixture meets the requirement, is about 5000-Rubber asphalt case.

3. The rubber asphalt of the scheme is mainly used for special asphalt pavements, OGFC or thin-layer pavement pavements; the rubber asphalt can also be used for the conventional grading type (AC/SMA), has more excellent performance, is obviously superior to the level of high-performance rubber asphalt, and mainly has better high-temperature performance, better water damage resistance and better water permeability.

Further, the asphalt is petroleum asphalt.

Further, the rubber powder is 40-120 meshes.

Further, the first crosslinking assistant is one of DCP dicumyl peroxide, DTBP di-tert-butyl peroxide and 2, 5-dimethyl-2, 5-di-tert-butyl hexane peroxide.

Further, the second crosslinking assistant is one of sulfur, TMTD, DCP, pro-M or pro-D.

The application also discloses a preparation method of the high-viscosity rubber asphalt, which comprises the following steps:

s1: heating aromatic oil to 135-160 ℃, adding SBS and oxidized polyethylene wax in a metering manner, keeping the temperature and stirring for 60-120 min, wherein the stirring speed is 500-800 rpm;

s2: adding a first crosslinking auxiliary agent into S1, stirring for 60-90 min at the stirring speed of 500-800 rpm under the heat preservation condition, and preparing to obtain a polymer mother liquor A;

s3: heating the asphalt to 160-185 ℃, adding the polymer mother liquor A, and stirring for 60-90 min at the stirring speed of 500-800 rpm under the heat preservation condition;

s4: metering rubber powder, stirring for 1-2 h under heat preservation, wherein the stirring speed is 500-800 rpm;

s5: shearing the mixture obtained in the step S4 for 15-50 min by a high-speed shearing emulsifying machine, wherein the shearing rate is 5000-12000 rpm, and then grinding once by using a colloid mill;

s6: and adding a second crosslinking auxiliary agent into the ground mixture, and stirring for 3-5 hours at the heat preservation temperature of 160-185 ℃ and the stirring speed of 500-800 rpm to obtain the high-viscosity rubber asphalt.

Drawings

FIG. 1 is a partial cross-sectional view of a special stirring apparatus in example 10 of the present invention;

fig. 2 is a sectional view taken along the line a-a in fig. 1.

Reference numerals in the drawings of the specification include: the stirring shaft 10, the stirring blades 11, the connecting rod 12, the sliding hole 13, the elastic membrane 14, the shaft sleeve 15, the pull rod 16, the elastic piece 17, the interception plate 18 and the through hole 19.

Detailed Description

The following is further detailed by way of specific embodiments:

example 1:

the high-viscosity rubber asphalt comprises 100 parts of asphalt, 5 parts of rubber powder, 3 parts of SBS, 1.5 parts of oxidized polyethylene wax, 0.1 part of first crosslinking aid, 3 parts of aromatic oil and 0.3 part of second crosslinking aid.

Wherein the asphalt is petroleum asphalt, the rubber powder is 40-120 meshes, and the first crosslinking assistant is one of DCP dicumyl peroxide, DTBP di-tert-butyl peroxide and 2, 5-dimethyl-2, 5 di-tert-butyl hexane peroxide (bis-25); the second crosslinking assistant is one of sulfur, TMTD, DCP, promoter M or promoter D.

The preparation method of the high-viscosity rubber asphalt comprises the following steps:

s1: heating the aromatic oil to 135-160 ℃, adding SBS and oxidized polyethylene wax in a metering manner, keeping the temperature and stirring for 60-120 min, wherein the stirring speed is 500-800 rpm.

S2: and adding a first crosslinking auxiliary agent into S1, and stirring for 60-90 min at the stirring speed of 500-800 rpm under the heat preservation condition to prepare the polymer mother liquor A.

S3: heating the asphalt to 160-185 ℃, adding the polymer mother liquor A, and stirring for 60-90 min at the stirring speed of 500-800 rpm under the heat preservation condition.

S4: and (3) metering and adding rubber powder, and stirring for 1-2 hours at the stirring speed of 500-800 rpm.

S5: and (4) shearing the mixture obtained in the step (S4) for 15-50 min by using a high-speed shearing emulsifying machine, wherein the shearing rate is 5000-12000 rpm, and then grinding once by using a colloid mill.

S6: and adding a second crosslinking auxiliary agent into the ground mixture, and stirring for 3-5 hours at the heat preservation temperature of 160-185 ℃ and the stirring speed of 500-800 rpm to obtain the high-viscosity rubber asphalt.

Examples 2 to 13 and comparative examples 1 to 3:

the difference from the example 1 is only that the mixture ratio of each component is different, and the specific component mixture ratio is shown in the following table 1.

Table 1 shows the composition ratios of examples 1 to 13 and comparative examples 1 to 3

	Asphalt	Rubber powder	SBS	Oxidized polyethylene wax	Aromatic oil	First crosslinking assistant	Second crosslinking assistant
								Example 1	100	5	3	1.5	3	0.1	0.3
Example 2	100	10	3	1.5	3	0.1	0.3
								Example 3	100	15	3	1.5	3	0.1	0.3
Example 4	100	10	2	1.5	3	0.1	0.3
								Example 5	100	10	7	1.5	3	0.1	0.3
Example 6	100	10	3	0.5	3	0.1	0.3
								Example 7	100	10	3	3	3	0.1	0.3
Example 8	100	10	3	1.5	1	0.1	0.3
								Example 9	100	10	3	1.5	4	0.1	0.3
Example 10	100	10	3	1.5	3	0.04	0.3
								Example 11	100	10	3	1.5	3	0.4	0.3
Example 12	100	10	3	1.5	3	0.4	0.2
								Example 13	100	10	3	1.5	3	0.4	0.6
Comparative example 1	100	10	3	0	3	0.1	0.3
								Comparative example 2	100	10	0	1.5	3	0.1	0.3
Comparative example 3	100	10	3	1.5	3	0	0.3

Example 14:

the difference from embodiment 2 is that a special stirring device is adopted in step S3 of the preparation method, and as shown in fig. 1 and fig. 2, the special stirring device includes a horizontally fixed stirring drum, an inlet is provided at the left end of the stirring drum, an outlet is provided at the right end of the stirring drum, a stirring shaft 10 is rotatably connected in the stirring drum, wherein the stirring shaft 10 is hollow, a pipeline is connected to both ends of the stirring shaft 10 through a rotary joint, a plurality of stirring blades 11 are fixed on the stirring shaft 10, a heating medium (gas, water, liquid metal, etc.) flows through the stirring shaft 10 through the pipeline, thereby heating the stirring shaft 10 and the stirring blades 11, and a driving mechanism is further provided for driving the stirring shaft 10 to rotate.

There is connecting rod 12 along sliding connection in (mixing) shaft 10, connecting rod 12 and (mixing) shaft 10 are coaxial to be set up, set up a plurality of slide opening 13 that are located between stirring vane 11 on the outer wall of (mixing) shaft 10, it has elastic membrane 14 that is located slide opening 13 department to bond on the (mixing) shaft 10 outer wall, PDMS membrane that can be able to bear 200 ℃ high temperature is selected for use to elastic membrane 14 in this embodiment, be equipped with a plurality of moving mechanism on the connecting rod 12, moving mechanism is including fixing axle sleeve 15 on connecting rod 12, be fixed with a plurality of pull rods 16 on axle sleeve 15, a plurality of pull rods 16 are along axle sleeve 15's circumference equipartition, fixed elastic component 17 at the free end of pull rod 16, elastic component 17 is located slide opening 13, and with elastic membrane 14 fixed connection, elastic component 17 can select for use.

A plurality of through holes 19 are formed in the interception plate 18, the through holes 19 are irregularly distributed on the interception plate 18, and the through holes 19 on the interception plate 18 in each moving mechanism do not completely coincide along the axial projection of the stirring shaft 10, so that when a heating medium passes through the stirring shaft 10, the heating medium enters the slide hole 13, the elastic membrane 14 is deformed outwards, and meanwhile, when the heating medium passes through the interception plate 18, an impact force is given to the interception plate 18, so that the interception plate 18 moves in the flow direction, the elastic member 17 is driven to generate a force towards the outside of the slide hole 13, the elastic membrane 14 is deformed inwards, so that the elastic membrane 14 is in a continuously convex and concave state in the stirring process, and asphalt near the stirring shaft 10 moves outwards and is not attached to the stirring shaft 10 all the time, preventing the asphalt from aging.

Comparative example 4:

the difference from the embodiment 2 is that the aromatic oil, the first crosslinking aid, the SBS, the rubber powder, the oxidized polyethylene wax and the second crosslinking aid are directly added into the asphalt after the temperature of the asphalt is raised, stirred and mixed, and then sheared by a high-speed shearing emulsifying machine and ground by a colloid mill.

And (3) carrying out performance test on the high-viscosity rubber asphalt obtained in the examples 1-14 and the comparative examples 1-4, wherein the test method and the standard are as follows: JTG F40-2004 technical Specification for Highway asphalt pavement construction, the test results are shown in Table 2.

Table 2 shows the results of the performance tests of examples 1 to 14 and comparative examples 1 to 4

In combination with table 2, it can be seen that:

1: the dynamic viscosity of the rubber asphalt obtained by the method is high, and the dynamic viscosity at 60 ℃ is improved to 12 multiplied by 10⁴The adhesive force between the asphalt and the aggregate of the asphalt mixture is very strong (the dynamic viscosity at 60 ℃ reflects the cohesive force of the asphalt), the advantages are obvious in Kentunberg scattering and leakage loss performance of the asphalt mixture; meanwhile, the high-temperature performance (dynamic stability) of the asphalt mixture is reflected, and the high-temperature performance (dynamic stability) of the asphalt mixture meets the requirement, is about 5000-.

2: the rubber asphalt obtained by the method is mainly used for special asphalt pavements, OGFC or thin-layer pavement pavements; of course, the rubber asphalt can also be used for the conventional grading type (AC/SMA), has more excellent performance, is obviously superior to the level of high-performance rubber asphalt, and mainly has better high-temperature performance, better water damage resistance and better water permeability.

OGFC-13 application test:

the high-viscosity rubber asphalt prepared in the examples 2, 5-7, 10, 11 and 14 and the comparative examples 1-4 and graded stone are stirred at high temperature, paved and rolled to prepare an asphalt mixture, the grading standard is OGFC-13, the test result is shown in the following table 3, and A in the table represents the Schrenberg leakage loss; b represents kentucky loss; c represents the soaking Ma's residual stability; d represents the freeze-thaw split residual strength ratio.

Table 3 shows the test results of OGFC-13 asphalt mixture

As can be seen from table 3 above:

the mixture obtained by adopting the rubber asphalt of the application shows very good dynamic viscosity performance, the dynamic stability at 60 ℃ is more than 5000 times/mm, and the dynamic viscosity is far higher than that of the mixture prepared by a comparative example; secondly, the Schrenberg leakage loss and the Kentaburg scattering loss are also far lower than the mixture prepared by the comparative example; in addition, the water stability of the mixture prepared by the method also shows obvious advantages, and the ratio of the soaking martensite residual stability to the freeze-thaw cleavage residual strength is superior to that of the mixture prepared by a comparative example.

The foregoing is merely an example of the present invention and common general knowledge of the known specific materials and characteristics thereof has not been described herein in any greater extent. It should be noted that, for those skilled in the art, without departing from the present invention, several changes and modifications can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicability of the patent. The scope of the claims of the present application shall be determined by the contents of the claims, and the description of the embodiments and the like in the specification shall be used to explain the contents of the claims.

Claims (6)

1. The high-viscosity rubber asphalt is characterized in that: the rubber composition comprises, by weight, 100 parts of asphalt, 5-15 parts of rubber powder, 2-7 parts of SBS, 0.5-3 parts of oxidized polyethylene wax, 0.04-0.4 part of first crosslinking aid, 1-4 parts of aromatic oil and 0.2-0.6 part of second crosslinking aid.

2. The high-viscosity rubber asphalt according to claim 1, characterized in that: the asphalt is petroleum asphalt.

3. The high-viscosity rubber asphalt according to claim 1, characterized in that: the rubber powder is 40-120 meshes.

4. The high-viscosity rubber asphalt according to claim 1, characterized in that: the first crosslinking assistant is one of DCP dicumyl peroxide, DTBP di-tert-butyl peroxide and 2, 5-dimethyl-2, 5 di-tert-butyl hexane peroxide.

5. The high-viscosity rubber asphalt according to claim 1, characterized in that: the second crosslinking assistant is one of sulfur, TMTD, DCP, promoter M or promoter D.

6. The method for producing the high-viscosity rubber asphalt as claimed in any one of claims 1 to 5, wherein: the method comprises the following steps:

s1: heating aromatic oil to 135-160 ℃, adding SBS and oxidized polyethylene wax in a metering manner, keeping the temperature and stirring for 60-120 min, wherein the stirring speed is 500-800 rpm;

s2: adding a first crosslinking auxiliary agent into S1, stirring for 60-90 min at the stirring speed of 500-800 rpm under the heat preservation condition, and preparing to obtain a polymer mother liquor A;

s3: heating the asphalt to 160-185 ℃, adding the polymer mother liquor A, and stirring for 60-90 min at the stirring speed of 500-800 rpm under the heat preservation condition;

s4: metering rubber powder, stirring for 1-2 h under heat preservation, wherein the stirring speed is 500-800 rpm;

s5: shearing the mixture obtained in the step S4 for 15-50 min by a high-speed shearing emulsifying machine, wherein the shearing rate is 5000-12000 rpm, and then grinding once by using a colloid mill;

s6: and adding a second crosslinking auxiliary agent into the ground mixture, and stirring for 3-5 hours at the heat preservation temperature of 160-185 ℃ and the stirring speed of 500-800 rpm to obtain the high-viscosity rubber asphalt.

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